1. Field of the Invention
The present invention relates to an improved loom heald control means for operating the warp healds of a loom, specifically of a Jacquard machine, including two rods mounted at one end to the wire, which said two rods are reciprocable between an upper and a lower position, including further flexible rod retaining members supported at one end in a supporting means and operative to retain said rods in their respective end positions, the rods and their corresponding retaining members having complementary shaped engaging sections located at the respective free ends of said rods and said retaining members, which engaging sections are movable into and out of engagement relative to each other, and including an electromagnet located between said retaining members and supported by said supporting means and operative to deflect said retaining members relative to said rods such to move said retaining members into and out of engagement with their respective corresponding rod.
The loom heald control means of a Jacquard machine comprises generally two rods, which are reciprocated by knives and one end of the respective rods is mounted to a wire lid over a set of pulleys and the respective opposite ends of the rods are provided with means operative to retain the rods in a given position. Furthermore, a support means is provided which is movable into and out of engagement with the retaining means at the rods and finally there is provided a control means, with which the rods are moved into engagement and out of engagement with the retaining means.
2. Description of the Prior Art
Such a loom heald control means is disclosed in British Pat. No. 2 047 755, in which the retaining means and control means are combined to a structural unit. This structural unit termed below as control device comprises two flexible retaining members and an electromagnet located between the retaining members and operative to deflect the retaining members relative to the electromagnet and to move the retaining members and the rods into and out of engagement. The retaining members are mounted at one end to a support and the electromagnet projects from the same support and is provided with an exposed core member. The retaining members and rods are provided with a hook and an opening, respectively.
If during operation of the loom one rod is lifted by its corresponding knife, the corresponding retaining member will engage by means of its hook into the opening of the rod and retain the rod in its position as long as the electromagnet is not excited. Upon the excitation of the electromagnet the retaining member will be pulled against the exposed core member of the electromagnet such that the hook provided on the retaining member can no longer engage into mentioned opening.
The drawback of this known design is the necessity of building up a relatively strong magnetic field in order to pull the two retaining members against the core of the electromagnet. Furthermore, the weakening of such magnetic field must be considered, which arises due to the nonsynchronous attraction of the retaining members by the electromagnet and accordingly, premature closing of the magnetic circuit one side of the electromagnet. This presupposes a large output of the electromagnet leading in turn to a higher and undesirable heating thereof. A decrease of the power consumption of the electromagnet by decreasing the air gap is limited because due to the shape of the hook a certain deflecting movement is necessary and also because due to their spring action the retaining members are manufactured from a magnetically hard material having a relatively high remanence.